Swat is a todo application manager, written in gtk ruby. Its basically a wrapper around org-mode of emacs. Features:

* Manage your todos, add them according to priority and category.
* Move your todos to wish list, when not feeling like working on them.
* libtomboy bindings for global shortcut(Alt-F11).
* Nice stats for number of tasks finished and added.
* All your todos are in a .org file and hence can be managed from Emacs as well.
* System tray integration.
* See completed todos